This invention claims priority of the German filed patent application DE 100 31 720.0 which is incorporated by reference herein.
The invention concerns an apparatus for objective changing. In addition, the invention also concerns a microscope having an apparatus for objective changing. The microscope can be configured as a scanning microscope or also as a confocal microscope.
Microscopes have been known from the existing art for some time. Objective changing is generally performed by means of a revolving nosepiece.
European Patent Application EP-A-0 124 980 discloses an inverted microscope in which the revolving nosepiece sits below the specimen that is to be observed. The advantage of the inverted microscope design is that the revolving nosepiece does not interfere with the space above or next to the specimen as the objective is changed. A certain movement space is needed to pivot in the objectives arranged on the revolving nosepiece. The inverted microscope has the disadvantage that observation must always take place through a glass plate as a specimen is being observed and manipulated. In addition, it is more difficult to use incident illumination because the immersion liquid often penetrates into the optical system.
German Patent Application DE-A-29 22 212 discloses a microscope having an associated micromanipulator. The tip of the micromanipulator touches the specimen being examined, and at high magnification is located very close to the objective. Considering that not just one manipulator but several of them act on the specimen being examined, and furthermore from both sides, it is easy to imagine that if objective changing on an upright microscope is performed carelessly, the manipulators can be damaged. To prevent damage, the manipulators must be removed for the objective change, and reoriented after the change. This is time-consuming and inefficient.
German Patent Application DE-A-198 34 829 discloses a microscope that possesses a revolving nosepiece for changing the objectives. The revolving nosepiece is configured in such a way that the individual objectives mounted on the revolving nosepiece are arranged with their optical axes perpendicular to the rotation axis of the nosepiece. The rotation axis of the revolving nosepiece is at least partially a component of the optical beam path. In the region of the specimen, the objective being pivoted in or out requires sufficient space in the X-Z plane. Arrangements for specimen manipulation cannot be provided in this region, since the risk of damage is too great.
It is the object of the invention to create an apparatus for objective changing, which requires only a small space. A further intention is that the adjustment or alignment of the additional equipment items is not necessary.
The object is achieved by an apparatus for objective changing which comprises: an inventory of at least one objective which defines a longitudinal axis, an objective storage position in said inventory and a reference objective position defined by a retaining element wherein during the objective change the objective with its longitudinal axis is movable in the vicinity of the retaining element substantially coaxially with an optical axis defined by the objective in the reference objective position.
It is the object of the invention to create an objective changing device that makes available, in the region of a specimen being observed, sufficient space that damage to additional equipment items is avoided. A further intention is that the adjustment or alignment of the additional equipment items is not be modified during objective changing.
The stated object is achieved by an apparatus which comprises; an inventory of at least one objective wherein the objective defines a longitudinal axis, an objective storage position, a reference objective position wherein the objective change takes place between the objective storage position and the reference objective position, an optical axis is defined by the objective in the reference objective position, and a retaining element defines the reference objective position; wherein during the objective change the objective with its longitudinal axis is movable, in the vicinity of the retaining element, substantially coaxially with the optical axis.
A further object of the invention is to create a microscope in which the objective change is performed in such a way as to influence or limit the region around the specimen being examined as little as possible. Damage to manipulators resulting from the objective change is to be avoided.
The stated objective is achieved by a microscope comprising: an objective changing device, an inventory of at least one objective wherein the objective defines a longitudinal axis, an objective storage position in said inventory and a reference objective position defined by a retaining element wherein during the objective change the objective with its longitudinal axis is movable in the vicinity of the retaining element substantially coaxially with an optical axis defined by the objective in the reference objective position.
An advantage of the invention is that during the objective change, there is almost no influence on the space around an objective located in the reference objective position. The manipulators acting on a specimen (microtools, micropipettes, microelectrodes, microneedles) need to be adjusted and aligned with the specimen only once. The objective change into the reference objective position, which is defined by a retaining element, is accomplished in such a way that during the objective change, the longitudinal axis of the objective is movable, in the vicinity of the retaining element, substantially coaxially with the optical axis of the objective.
Since a conventional revolving nosepiece requires considerable space around the reference objective position because of the pivoting motion into the next reference objective position, the risk of damage to the manipulators exists. The apparatus according to the present invention has the further advantage that little space laterally around the reference objective position is required during the objective change. The manipulators no longer need to be removed from the specimen during the objective change and then realigned. The complex, time-consuming, and productivity-reducing alignment process can be eliminated by the invention.
A microscope that uses the apparatus according to the present invention is configured in such a way that the stand has configured in it at least one opening through which at least one objective is movable from the objective storage position into the reference objective position. It is further advantageous that the microscope, in the stand region of the objective-side beam path (the microscope head), is insignificantly wider than the diameter of the objective. Sufficient room is thus created for arrangement of the numerous manipulators acting on the specimen. The overall result of this is that the micromanipulators acting on the specimen being examined remain in their predetermined positions during the objective change.
In addition, the microscope can be configured as a scanning microscope or as a confocal scanning microscope.